With development of present computers and electronic devices, it is always a target for people to pursue high and efficient transmitting speed of data. The same purpose also pushes the industry to set up more advanced specification of data transmission. However, transition of different specifications of data transmission is limited not only by available technology but also people who own the devices with old specification. The later exists because users hope the devices can be used for a long time.
Meanwhile, market demands lead to more compact electronic devices. In addition to simplified internal design of electronic devices, external slots are needed to be selected for the maximum interfaces. Otherwise, the expectation mentioned above can not be fulfilled. For example, universal serial bus (USB) 2.0 specification is the most applicable interface for data transmission. A laptop might have three to seven USB 2.0 connector slots (female connectors) for connecting peripheral products, such as a mouse, speaker or a card reader. However, with the size of laptops becoming smaller and more compact, less number of USB 2.0 female connectors can be fabricated in the available space within the laptop, not to mention other connectors with different data transmitting specifications. For an external hard disk drive, a connector for higher data transmission adopts external serial advanced technology attachment (eSATA) or even USB 3.0 specification. Without female connectors in the laptop, users can not access the external hard disc drive. It is difficult for laptop designers to choose suitable combination of connectors.
Please refer to FIG. 1. U.S. Pat. No. 7,517,253 discloses a compound female connector for USB 2.0 and eSATA specifications. The female connector has a casing, an eSATA terminal set and an USB terminal set. The casing has a cavity and a terminal seat being disposed in the cavity. The eSATA terminal set is mounted on the terminal seat and has side eSATA terminals and middle eSATA terminals. The middle eSATA terminals are disposed between the side eSATA terminals and mounted on the terminal seat. The USB terminal set is mounted on the terminal seat opposite to the eSATA terminal set and has multiple interior USB terminals and multiple exterior USB terminals. The exterior USB terminals respectively connect the middle eSATA terminals to transmit signals via the middle eSATA terminals. Therefore the female connector is compatible with USB 3.0 specification and is compact with the single terminal seat.
Those skilled in the art will know that '253 patent has below defects. First, it needs to form eSATA terminals exclusively for connecting with an eSATA connector. Total 9 terminals are used. That means various tools are required. It costs more than an eSATA female connector with single form of terminals. Second, '253 patent uses one housing to fix all terminals. Since the inner space of the housing is small, different kinds of terminals are not easy to get fixed one by one even if the assembly is done by machine. During assembly of the female connector, short circuit will easily occur to decrease the yield rate.
In order to overcome the defects mentioned above, the inventor came up with the present invention. Two housings are used to simplify assembly. The present invention has advantages of low cost and easy assembly.